Naomi Osaka suffered a shock second-round exit to Karolina Muchova at the Madrid Open, but there was no such trouble for Simona Halep as she held off Zheng Saisai.

Second seed Osaka was playing just her second match on clay since the 2019 French Open due to injury issues and became the latest big name to fall at the hands of Muchova.

The world number 20, who had already defeated two top-five players this season, prevailed 6-4 3-6 6-1 in a time of one hour and 49 minutes in the Spanish capital.

Osaka has now lost two of her last three matches, having been eliminated from the Miami Open quarter-finals by Maria Sakkari at the end of March.

"I think today for me it was quite different from the last time I lost in Miami, and I actually think I played much better here, so I'm very happy about that," Osaka said.

"I think what I can take away from this is that I tried my best throughout the entire match. I think tennis-wise, I felt I was too defensive in the first set.

"I wouldn't say I’m happy that I lost, but I think I learned a lot. So that's all I can hope for."

Two-time champion Halep has yet to drop a set in this year's tournament after seeing off unseeded opponent Zheng 6-0 6-4.

Halep took nine games in a row at the start of the match but, like in her opening-round win over Sara Sorribes Tormo, she had to hold off a late surge from her opponent to advance.

Next up for Halep is a last-16 showdown with Elise Mertens, who beat Elena Rybakina 7-6 (7-4) 7-5 in the last of Sunday's matches.

Fifth seed Aryna Sabalenka safely advanced earlier in the day thanks to a 6-3 6-3 win against Daria Kasatkina, while Sakkari beat Anett Kontaveit 6-3 6-1.

Sabalenka was on course to face Victoria Azarenka for a place in the quarter-finals, but the Belarussian withdrew from her match with Jessica Pegula because of a back injury.

Elsewhere, Jennifer Brady, who knocked out fellow American Venus Williams in the first round, eased past Jelena Ostapenko 6-2 6-1.

Brady faces a tricky test in the next round with Anastasia Pavlyuchenkova, who defeated sixth seed Karolina Pliskova 6-0 7-5, seeking another scalp.

Ash Barty overcame Tamara Zidansek and her own disjointed performance to reach the third round of the Madrid Open on Saturday.

The Australian triumphed 6-4 1-6 6-3 after nearly two hours on court to extend her winning streak on clay to 13 matches.

Barty will face reigning French Open champion Iga Swiatek in the next round, the 19-year-old having eased past Laura Siegemund 6-3 6-3 in a contest where she failed to take 10 match points before getting over the line.

Barty endured a more troubled contest with Zidansek, landing just 51 per cent of her first serves.

Zidansek lost the opener after a wayward forehand at 4-4 but was authoritative in the second as she won a set against a top-10 player for the first time.

However, a series of errors early in the decider allowed world number one Barty to open up a lead she did not relinquish. Barty was champion at Roland Garros in 2019 but skipped last year's Paris grand slam, so the clash with Swiatek will pit together the two most recent French Open winners.

"[It was] a really tough match," Barty said after edging out Zidansek. "I felt my margins were a little bit off. I made a lot of errors. I think I was missing in the right way, but still just a foot or two here or there makes a big difference. I felt like there were probably too many loose ones for me today.

"I don't think there was a lot in it by any means. We had a lot of close games in the first set, early in the second set. In the third, as well, there were a lot of close games. I think the response early in the third was good. I was a bit more aggressive, was able to bring the match back on my terms."

Petra Kvitova set up a meeting with Veronika Kudermetova – who knocked out defending champion Kiki Bertens – after overcoming long-time rival Angelique Kerber 6-4 7-5.

Kerber got the opening break in each set, only to drop serve in the next game, with Kvitova ultimately rewarded for powerful hitting as she ended the contest with 33 winners to her opponent's 14.

"I served very well, especially in the important points," said Kvitova, who leads the head-to-head record 8-6. "I think we really played very well. She even served very well, as well. It was tough to attack her serve."

Fifteenth seed Johanna Konta suffered a straight-sets loss to Anastasija Sevastova, while Ons Jabeur fought back to beat Sloane Stephens.

Naomi Osaka quickly adapted to playing again on clay as she was among the seeds to triumph in Friday's action at the Madrid Open.

Osaka had not featured on the red dirt since a third-round exit at the 2019 French Open, missing out on competing on the surface last year due to injury.

This year's Australian Open champion stumbled out of the blocks against Misaki Doi, quickly falling 3-0 behind in the opener, but recovered from the early setback to prevail in straight sets.

The second seed hit 26 winners in a 7-5 6-2 triumph over her compatriot, who has now lost all three of their meetings on the WTA Tour.

"You obviously want to play well against a player that's from the same country," Osaka said.

"I never really know what to expect because I feel like she always plays better when I play against her, so it's a bit tough to manage controlling my emotions. But I think I was able to do it pretty well."

Simona Halep also won in her opener at the event, the third seed racing through the first set before holding off a fightback from Sara Sorribes Tormo in the second.

Halep – who needed 83 minutes to clinch a 6-0 7-5 victory – has been crowned champion twice in Madrid, the first time coming in 2016 before she returned a year later to successfully defend the title.

Aryna Sabalenka wasted little time in seeing off the challenge of Vera Zvonareva, the fifth seed producing 37 winners in a 6-1 6-2 win, her first ever in the event.

Maria Sakkari found the going much tougher before eventually ousting Amanda Anisimova, losing the first seven games in a row before rallying for a 0-6 6-1 6-4 triumph.

Daria Kasatkina was also pushed in her opener, with a 4-6 6-4 7-6 (7-1) win over Irina-Camelia Begu taking just over three hours.

Karolina Pliskova had to go the distance after falling a set behind against Coco Gauff, while two-time finalist Victoria Azarenka came out on top in a deciding set against Ekaterina Alexandrova.

In the final match on a busy day, Jennifer Brady won 6-2 6-4 in an all-American clash with Venus Williams.  

Jil Teichmann saved six match points in a stunning defeat of Elina Svitolina before Ash Barty breezed into the second round of the Madrid Open on Thursday.

Teichmann produced an astonishing fightback to beat fourth seed Svitolina 2-6 6-4 7-6 (7-5) at the Caja Magica.

Unseeded Swiss Teichmann came from a set and a break down to claim the scalp of the world number five, who squandered a commanding 5-1 lead in the final set.

Svitolina saw six match points come and go in an incredible deciding set, opportunities she was left to rue when the 40-ranked Teichmann won a tie-break to end a contest that took two hours and 33 minutes to settle.

World number one Barty extended her winning run on clay to 12 matches with a 6-2 6-1 success over Shelby Rogers.

Barty claimed her third title of the year in Stuttgart last weekend and the Australian needed just an hour to send Rogers packing, losing just two points on her first serve and not facing a single break point.

French Open champion Iga Swiatek was also an emphatic winner, easing past another American in the form of Alison Riske 6-1 6-1.

Swiatek, making her debut in this tournament, has won 16 consecutive matches on clay after blowing Riske away.

Defending champion Kiki Bertens beat 15-year-old Victoria Jimenez Kasintseva 6-4 6-0, while Petra Kvitova progressed when opponent Marie Bouzkova retired due to hand injury after the Czech won the first set.

Garbine Muguruza was forced to withdraw ahead of her meeting with Sloane Stephens due to a leg injury. Belinda Bencic, Angelique Kerber and Johanna Konta were among the other winners in the Spanish capital.

Sorana Cirstea claimed the Istanbul Open title without dropping a set after overcoming top seed Elise Mertens 6-1 7-6 (7-3) in the final.

Cirstea secured just her second tournament triumph on the WTA Tour – and first since Tashkent in 2008 – in a contest of two contrasting sets on Sunday.

The Romanian dominated in the opener, breaking three times as her opponent committed 16 unforced errors while failing to hold serve.

However, Mertens responded impressively to seize control of the second set, some superb groundstrokes allowing her to open up a commanding 5-2 lead.

Cirstea hit back to take the next four games in a row and while unable to serve out for the match when 6-5 up, she would not be denied a long overdue success in the tie-break.

Victory was secured with a crunching backhand winner on the first of three match-point opportunities, ending a see-saw set that had spanned 67 minutes.

Mertens had reached the final by ending a nine-match winning run for Veronika Kudermetova, who just so happened to be her doubles partner at the event in Turkey.

Ash Barty came from a set down for the third time this week as the world number one continued a superb 2021 with victory at the Stuttgart Open.

Barty overcame Aryna Sabalenka 3-6 6-0 6-3 to lift an 11th career title and her third of the season after successes at the Miami Open and the Yarra Valley Classic in Melbourne.

It proved to be another comeback triumph against a top-10 opponent for Barty, who saw off Karolina Pliskova and Elina Svitolina in the quarter and semi-finals respectively.

Sabalenka was ready to seize upon another sluggish Barty start and forced three break points at 3-2 in the opener.

The Australian was able to hang on that time, but Sabalenka fashioned two more and a botched Barty drop shot meant it was fifth time lucky.

The rapid progress of set two suggested Barty had merely been warming up, snaffling her third break point at 1-0 and dispatching a magnificent forehand cross-court winner to surge 4-0 ahead.

A bagel felt inevitable from that point and, after a 20-minute second set, Sabalenka was sinking without a trace when she slipped 3-0 behind in the decider.

The fifth seed broke back before being undermined by an untimely double fault at 3-2 – one of 39 unforced errors – and Barty faced down three break points in the following game.

A superb display, featuring 26 winners and five break points converted from 12 opportunities, concluded when Barty wrapped things up on her second match point.

Ash Barty will meet Aryna Sabalenka in the Stuttgart Open final after Simona Halep's quest to win the tournament for the first time fell short.

World number three Halep had claimed straight-set wins over Ekaterina Alexandrova and Marketa Vondrousova en route to the semi-finals, but met her match in the form of Belarusian Sabalenka, who triumphed 6-3 6-2.

A nine-time singles champion, Sabalenka made it into a 14th career final without conceding a single break, as she managed to keep Romanian Halep at arm's length.

Standing between Sabalenka and a 10th singles title is world number one Barty who, on her 25th birthday, came from behind to defeat Elina Svitolina 4-6 7-6 (7-5) 6-2.

Making her tournament debut in Stuttgart, Barty had overcome Laura Siegemund and Karolina Pliskova, but found herself at 5-4 down in the second set, with Svitolina serving for the match.

The fourth seed failed to take her chance, with Barty breaking and subsequently biting back in the tie-break, before carrying the momentum into the decider to claim a third straight win over Svitolina.

Top seed Elise Mertens made it to her second Istanbul Open as she saw off her doubles partner and birthday girl Veronika Kudermetova 6-1 6-4.

It means Mertens will be playing in two finals on Sunday, as she pairs up with Kudermetova again in the doubles showdown against Nao Hibino and Makoto Ninomiya.

Mertens' win ended Charleston champion Kudermetova's nine-match winning streak, and set up a final against the unseeded Sorana Cirstea, who defeated Marta Kostyuk 6-4 6-4.

World number one Ash Barty survived a scare to reach the semi-finals of the Stuttgart Open with a 2-6 6-1 7-5 win over Karolina Pliskova.

The Australian started slowly in the quarter-final of the WTA 500 tournament on Friday as Pliskova broke her serve twice in taking the first set, before Barty hit back with three breaks of her own to force a decider.

Barty was two points away from losing on five occasions as world number nine Pliskova served for the match at 5-4 in the final set.

But she broke the Czech's resolve eventually, sealing victory when Pliskova hit the ball long after a baseline rally.

The win was Barty's eighth consecutive victory over a top-10 opponent and she said in a media conference afterwards that facing top players in the world brings the best out of her.

"When you come up against top-10 opponents, you have to go to that level above to be able to compete. They force you to bring your best," Barty said.

"With a lot of the girls in the top 10, we've had plenty of matches that have gone either way, different experiences, so each time I love that challenge of testing myself against the best."

Barty will face Elina Svitolina in the semi-finals after she saved two match points to claim a 6-7 (4-7) 7-5 6-2 victory over Petra Kvitova.

In the other half of the draw, Simona Halep breezed through to the semi-finals with a 6-1 6-4 win over Ekaterina Alexandrova.

Halep clinically closed out the first set, and although Alexandrova showed more fight in the second, the world number three did not allow her a route back into the match.

Halep will face Aryna Sabalenka following the Belarusian's 7-5 4-6 6-1 win over Anett Kontaveit.

In the Istanbul Cup, top seed Elise Mertens secured her place in the semi-finals with a 6-4 6-4 win over Katerina Siniakova.

Mertens will face Veronika Kudermetova who fought back from a set down to clinch a 2-6 6-3 6-3 win over Ana Bogdan.

The other semi-final will see Sorana Cirstea play Marta Kostyuk. Cirstea progressed after Fiona Ferro, trailing 6-4, retired through injury while Kostyuk beat Ana Konjuh 7-5 4-6 6-3.

Simona Halep started her clay-court season in style at the Stuttgart Open as she saw off Marketa Vondrousova in straight sets on Thursday.

Second seed Halep is hunting her first appearance in a Stuttgart final, and she looked in fine form as she took just 56 minutes to dismiss Vondrousova 6-1 6-3.

Vondrousova – the 2019 French Open runner up – had won both of her previous meetings with Halep, but on this occasion she was no match for the world number three, who has won every major European clay-court tournament other than Stuttgart.

"Starting the clay-court season makes me very happy and motivated, extra motivated actually," Halep said in a post-match news conference.

"I missed playing matches. I had a few weeks without an official match and it was kind of tough when I started the match, but my mind was strong enough just to give focus on what I have to play. So, I did it great and today it was a great match.

"I was a little bit nervous before the match because I played twice against her and she beat me every time.

"It is important for my mind, for my game, because the clay-court season is going to be very tough. Now this match gave me confidence that my level is high, and if I keep doing the same thing, I will be good."

Facing Halep in the quarter-finals will be Ekaterina Alexandrova, who defeated world number 12 Belinda Bencic, and joining them in the final eight is Elina Svitolina, who defeated Angelique Kerber 7-6 (7-4) 6-3.

Two-time Stuttgart champion Kerber and Svitolina had faced off 13 times before Thursday's contest, and the Ukrainian is now 9-5 up in that head-to-head tussle.

While Aryna Sabalenka also progressed, Karolina Pliskova teed up a clash with top seed Ash Barty by coming from behind to beat Jelena Ostapenko 6-7 (7-9) 6-4 6-3.

At the Istanbul Open, top seed Elise Mertens also needed three sets to forge a path into the last night.

Mertens had to show her mettle in a contest which lasted over two hours, but she eventually got the better of Viktorija Golubic 6-4 4-6 6-1.

Veronika Kudermetova also made the last eight, as did Ana Bogdan, who fended off Barbora Kreijcova, while Fiona Ferro defeated Vera Zvonareva.

Carla Suarez Navarro revealed on Thursday she has overcome Hodgkin lymphoma, and the Spaniard is set to resume her tennis career.

The former world number six revealed last September she would undergo six months of chemotherapy after being diagnosed with the rare cancer.

Suarez Navarro vowed at the time to show "positivity in the face of adversity" and the 32-year-old has now announced she is cured.

The 32-year-old posted on social media: "Another step forward. Today I finished my treatment and overcame Hodgkin lymphoma.

"Thanks to all for your warm messages. Every word of support gave me strength during the past few months.

"All my gratitude to healthcare professionals who take care of us every day. I'M CURED!"

Carla Suarez Navarro announced two years ago that the 2020 season would be her last on the WTA Tour.

However, the WTA said she decided to has abandon that plan and would return to action, confirming her entry for the French Open which begins on May 30 in Paris.

Athletes expressed relief and vowed to continue the fight for reforms after a jury in Minnesota found a former police officer guilty in the May 2020 death of George Floyd. 

Derek Chauvin was convicted of second-degree murder, third-degree murder and second-degree manslaughter on Tuesday, nearly 11 months after he knelt on Floyd's neck and back for more than nine minutes during an arrest. 

Floyd's death aged 46 sparked outrage across the United States, with athletes across multiple sports among those who called for justice. 

Tuesday's verdict in Minneapolis provided a measure of progress and sports figures, teams and leagues spoke out after the ruling. 

Basketball star LeBron James' reaction was among the most succinct as he tweeted simply: "ACCOUNTABILITY".

Boxing legend Mike Tyson tweeted: "Guilty. Justice served."

While similiar expressions of relief were common, most continued to lament the crime that sparked the case. 

"George Floyd lost his life, as many others have, unjustly. We can't forget that - that people are losing their lives," Brooklyn Nets head coach Steve Nash told reporters.

"On the other hand, it is a small gesture of justice and possibly hope for the future in that perhaps all the social justice movements - the NBA, the WNBA, the community at large - are really making an impact.

"I just hope that this is the type of statement by our justice system that gives hope and precedence for these type of verdicts to be the norm."

Petra Kvitova brushed aside Jennifer Brady as the defending champion cleared her first hurdle at the Stuttgart Open.

The Czech left-hander was the last winner of the German tournament, beating Anett Kontaveit in the 2019 final, with last year's event cancelled due to the pandemic.

Kvitova was handed a tough opening assignment against Australian Open runner-up Brady, but the American's streak of defeats since that Melbourne final defeat extended to three as Brady lost 6-4 6-3 in an hour and 32 minutes.

Two-time former Wimbledon champion Kvitova, seeded seventh, picked apart the Brady serve once in each set and fended off three break points across the contest to secure her last-16 place.

She was joined in the second round by powerful Belarusian Aryna Sabalenka, as the fifth seed scorched to a 6-2 6-2 win over China's Zhang Shuai.

Earlier, Ekaterina Alexandrova, Kontaveit, Anna Lena Friedsam and Laura Siegemund also went through to the last 16 of the WTA 500 event.

Meanwhile, Fiona Ferro caused a shock at the Istanbul Cup as she landed a 7-5 6-2 first-round win over former champion Petra Martic.

Martic, seeded second this year and ranked 21st in the world, landed the title in Istanbul in 2019 but was rolled over by French player Ferro in an hour and 45 minutes, in a match featuring seven breaks of serve.

Veronika Kudermetova followed her recent maiden title in Charleston with a nerve-jangling first-round win against Bernarda Pera, the fifth seed scrambling through 6-4 3-6 7-6 (7-4).

There was no such toil for top seed Elise Mertens, a 6-2 6-0 winner against Lara Arruabarrena, or for Daria Kasatkina, who dished out a 6-1 6-0 drubbing to Tereza Mrdeza.

Kasatkina is seeking her third title of 2021, having won previously in Melbourne and St Petersburg.

Anastasia Pavlyuchenkova bowed out of the WTA 250 event though, beaten 7-6 (7-2) 6-7 (8-10) 6-4 by compatriot Anastasia Potapova.

Belinda Bencic claimed her first win on clay since the 2019 French Open as she saw off teenager Nastasja Schunk at the Stuttgart Open.

The world number 12 eased to a 6-4 6-2 victory over the 17-year-old qualifier, who saved five match points in her final service game before Bencic closed things out.

"My love affair with clay is... I'm trying to improve myself on it," Bencic said after her first-round triumph.

"I think I'm getting better and I'm taking falls sometimes. I'm trying my best on this surface."

Maria Sakkari was similarly comfortable in progressing to the next round, hitting 24 winners as she dispatched Andrea Petkovic 6-2 6-2 on her debut at the tournament.

At the Istanbul Cup, four of the five scheduled matches were completed before rain stopped play with Anastasia Pavlyuchenkova and Anastasia Potapova level at a set apiece.

Eighth seed Wang Qiang fought back from a set down to beat Anastasia Gasanova 4-6 6-1 6-2.

There were also wins for Ana Konjuh, Katerina Siniakova and Viktorija Golubic.

Australian Astra Sharma scored a shock win over top seed Ons Jabeur in the final of the MUSC Health Women's Open, landing her first WTA Tour singles title.

The world number 165 made a slow start to the match but eventually overwhelmed Jabeur 2-6 7-5 6-1 in Charleston.

Having risen to 27th in the world rankings without a trophy to her name, the 26-year-old Jabeur looked to have an ideal opportunity to put that right.

Sharma recovered from the one-sided opening set to lead early in the second, and despite Jabeur getting it back on serve, the underdog surged ahead again to level the contest.

In her second WTA singles final and first for two years, Sharma went one step further than when she was runner-up in Bogota, racing through the deciding set as she swatted away Jabeur's threat.

Jabeur said the defeat was "very tough" to take, while Sharma said of her breakthrough week: "This has been an amazing event. I've really enjoyed playing here."

Ons Jabeur earned revenge on Danka Kovinic with a 6-3 6-0 hammering in the semi-finals of the MUSC Health Women's Open.

It was only a week ago the top seed was defeated by the same opponent on the same Charleston court at the same stage in the Volvo Car Open.

But a day on from needing just 45 minutes to hammer Nao Hibino 6-1 6-0, Jabeur required a little over 90 minutes to progress to Sunday's showpiece.

Jabeur is now 18-7 for the year, with only Garbine Muguruza holding more wins on the WTA Tour in 2021.

On the other side of the draw, Astra Sharma overcame Maria Camila Osorio Serrano 7-6 (7-5) 6-1.

It marks Sharma's second WTA final and her first in two years.